Ahrefs - Ahrefs is a toolset for SEO and marketing. We have tools for backlink research, organic traffic research, keyword research, content marketing & more. Give Ahrefs a try!
Optimage - Advanced image optimization tool
Smaller - Make your websites load faster
ImageOptim API - Web service for image compression
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Imagify - Optimize and resize images online and through your CMS.